Check valve

ABSTRACT

A check valve that can prevent sticking of a valve body and reliably perform an opening and closing action in a check vale having a simple structure and that does not use biasing means on the valve body. A check valve has support pieces of a valve body protruding in the valve body direction on a circular base seat forming an outflow window in the center inserted in a circular groove where a support member (retainer) is formed between an outflow opening and a valve seat and on an open edge of the outflow window formed in the center of the base seat, and the support pieces of the support member (retainer) that support the valve body have linear or planar support parts on the top portion for leveling at least in a radial direction of the base seat.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/655,838, filed Jul. 20, 2017, which is a continuation of U.S. patentapplication Ser. No. 14/803,522, filed Jul. 20, 2015, now U.S. Pat. No.9,739,236, both of which are incorporated herein by reference in theirentireties.

TECHNICAL FIELD

The present invention relates to a check valve used in a fuel passage ofa carburetor for the purpose of, for example, preventing reverse flow offuel.

BACKGROUND TECHNOLOGY

Check valves that allow fluid to flow out in only one direction andprevent the reverse flow have been known in the past, and various typessuch as a ball type, swing type, lift type, and disk type according tothe structure of a valve have been known. A purpose of the check valveis to prevent the reverse flow of fluid, and since overall the body isnot complicated, such as the disk type, it can be provided at a lowcost, is easily installed in the middle of a tubular body, and thereforeit is suitable for disposing, for example, in a fuel passage of acarburetor or the like.

Further, a disk type check valve forms an inflow opening and an outflowopening by a casing as described in, for example, Japanese UnexaminedPatent Application Nos. H10-288265 and H07-101066, and a ring-shapedvalve seat is formed there between to dispose a disk-shaped valve bodyhaving a larger diameter than the outflow opening and a smaller diameterthan the valve seat, that is biased in the outflow opening direction bya coil spring. When the fluid flows in from the inflow opening at apressure exceeding the biasing force of the coil spring, the valve bodyslides in the outflow opening direction by a large pressing force largerthan the biasing force of the coil spring acting on the valve body sothat the fluid that is coming in from the inflow opening through a gapwhich is formed on the outer periphery of the valve body in the valveseat, flows out. Conversely, when the fluid reverse flows from theoutflow opening direction, the valve body slides in the inflow openingdirection by the biasing force of the coil spring to close the inflowopening so as to prevent the reverse flow of the fluid.

A check valve using a further simple disk-shaped valve body described inJapanese Unexamined Patent Application No. 2010-60110 has also beenknown. This check valve 330, as illustrated in FIG. 5A, is configuredsuch that a valve body 332 and a valve seat 336 are inserted to attachin a valve holder 320, and assembled by engaging a projecting part 324to a groove 338 of the valve body 332. With this check valve 330, asillustrated in FIG. 5B, the valve body 332 becomes an open state byabutting onto a valve stopper 326 made from a curved longitudinal beammember, and also becomes a close state by abutting the valve body 332onto a valve seat 336 by reverse direction pressure.

Therefore, there is a large difference in the check valves described inPatent Application Nos. H10-288265 and H07-101066 in that anadvantageous effect is exhibited with a simple structure without usingmeans for pressing the valve body against the valve seat, for example,such as a coil spring.

Furthermore, a check valve illustrated in FIGS. 6A, 6B and 6C is aconventionally known check valve having a further simpler configurationthan the check valve that exhibits the similar advantageous effect witha simple structure without using biasing means illustrated in FIGS. 5Aand 5B. It is configured such that a case body 1 made of, for example,aluminum die cast, with a cylindrical inflow opening 2 and an outflowopening 3 formed respectively in both ends, as well as a cylindricalvalve seat 4, having a predetermined length, is formed in the axialdirection between the inflow opening 2 and the outflow opening 3Adisk-shaped valve body 5 with an outer diameter having a slightlysmaller diameter than the inner diameter of the valve seat 4 as well asa larger diameter than the inner diameter of the inflow opening 2, isdisposed with an ability to move in the axial direction of the valveseat 4, and a support member (retainer) 6 for the valve body 5 that isdisposed between the outflow opening 3 of the valve seat 4 and the valvebody 5.

Moreover, the support member (retainer) 6 is configured as illustratedin FIGS. 7, 8A, 8B and 8C where a disc-shaped base seat 61 that forms anoutflow window 62 in the center is fit into a circular circumferentialgroove formed between the outflow opening 3 and the valve seat 4 asillustrated in FIGS. 6A, 6B and 6C. Support pieces 64 for the valve body5 illustrated in FIGS. 6A, 6B and 6C are provided in an upwardlyprojecting manner (the valve body 5 direction) in an open edge 63 of theoutlet window 62 formed in the center of the base 61, as illustrated inFIGS. 7, 8A, 8B and 8C.

Also, in a check valve according to the present embodiment, asillustrated in FIG. 6A, a predetermined gap 41 is formed between the topsurface 43 of the valve seat 4 and the valve body 5 because the valvebody 5 disposed in the valve seat 4 is pressed in the outflow opening 3direction by the fluid normally entering from the inflow opening 2 to besupported by the support pieces 64 of the support member (retainer) 6.

Accordingly, the fluid entered from the inflow opening 2 flows towardsthe outflow opening 3 from the inflow window 62 of the support member(retainer) 6 via a space 42 formed between an inner peripheral surface44 of the valve seat 4 and the support piece 64 from the gap 41.

When the flow of the fluid changes in this condition, in other words,when the fluid that has been flowing toward the outflow opening 3 flowsin reverse and flows in the direction of the inflow opening 2, the openend 21 of the inflow opening 2 is closed by moving the valve body 5 inthe axial direction within the valve seat 4 because the fluid that hasbeen flowing toward the outflow opening 3 flows in reverse to operatethe check valve. That is, as illustrated in FIG. 6B, the valve body 5tightly contacts the open end 21 area of the inflow opening 2 of thevalve seat 4 due to the fluid pressure of the reverse flow and the checkvalve becomes the close state.

Documents of the Related Art

Japanese Unexamined Patent Application No. H10-288265

Japanese Examined Patent Application No. H07-101066

Japanese Unexamined Patent Application No. 2010-60110

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

However, the conventionally known support member (retainer) 6 is, forexample, machine pressed in a metal circular plate of an appropriatethickness and formed with support pieces 64 for supporting the center ofthe outflow window 62 and the valve body 5. Particularly, the tip endsof the support pieces 64 exhibit a horseshoe shape by bending the sidesurface upward. As a result, the support member (retainer 6) supportsthe valve body 5 in a point contact state by respective tip ends of eachsupport piece 64.

Accordingly, the valve body 5 is not supported by the support member(retainer) 6 in a stable state, and a protruding position of eachsupport piece 64 on the support member (retainer) 6 is in a positionseparated from the inner circumferential surface 44 of the valve seat 4.Because there is a large range of play in the valve body 5, when a fluidis applied to the valve body 5 at a pressure biased, for example, in adirection toward the outflow opening 3 with respect to the installationdirection, the valve body 5 will tilt to an angle where one end of thevalve body 5 is deeply inserted into a space 42 positioned between theinner circumferential surface 44 of the valve seat 4 and each of thesupport pieces 64 as shown in FIG. 6C. Therefore, the valve body 5 getsstuck due to the three (3) points of contact with the innercircumferential surface 44 of the valve seat 4, each of the supportpieces 64, and the top portion 43 of the valve seat 4, and as a result,there is a problem in that a state which inhibits the opening andclosing action of the check valve is induced.

To resolve the above problem, an object of the present invention is toprovide a check valve that can prevent sticking of a valve body andreliably perform an opening and closing action of a check valve having asimple structure and that does not use biasing means on the valve bodyas conventionally known.

Means for Solving the Problem

To resolve the above problems, the present invention is a check valveincluding: a case body in which a cylindrically shaped valve seat with acylindrically shaped inflow opening and outlet opening formedrespectively on each end and having an inner diameter larger than theinflow opening, and having a predetermined length in an axial directionformed between the inflow opening and the outlet opening; a disk shapedvalve body having an outer diameter slightly smaller than the innerdiameter of the valve seat and disposed with the ability to move in anaxial direction of the valve seat by a larger diameter than the innerdiameter of the outflow opening; a support member (retainer) of thevalve body disposed between the valve body and the outlet opening of thevalve seat; and a plurality of support pieces of the support member(retainer) protruded in the valve body direction on a disk shaped baseseat are formed centrally on an open edge of an outflow window formed inthe center of the base seat, where the support member (retainer) isinserted in a circular groove formed between the outflow opening and avalve seat; wherein each of the plurality of support pieces of thesupport member (retainer) supporting the valve body has a linear orplanar support part on the top portion for leveling of the base seat atleast in a radial direction.

Because each support piece of a support member (retainer) supporting avalve body has a linear or planar support part on the top portion forleveling at least in a radial direction of the base seat, the valvebody, when in a released state, can be supported in a stable state toprevent the generation of chattering, can narrow the gap between thesupport part and the inner circumferential surface of the valve seat toreduce the space formed between the support piece, and can preventsticking by the valve body by reducing the range of play in the valvebody.

Further, in the present invention, when integrally forming the supportmember (retainer) from a plate member, each support piece forms a linearsupport part on the top portion for leveling the valve body at least ina radial direction of the base seat by raising the support piece so asto face in a direction that intersects a direction toward a center pointinstead of the method of raising a support piece toward a center pointused conventionally.

Effect of the Invention

With the present invention, not only can a support member (retainer) beformed from the same material and process as used conventionally, butbecause the valve body can be prevented from sticking, a check valvehaving higher reliability can be provided in a simple structure similarto that used conventionally.

Moreover, in contrast to the support member (retainer) in theconventional technique where contact with the valve body is in pointcontact because the contact location with the valve body, i.e. theprotruding top portion, is a curved surface, the support member(retainer) of the present invention includes a flat protruding topportion as the contact location with the valve body, and therefore,contact with the valve body is planar contact which enables stabilitywhen holding the valve body.

Therefore, the valve body can move vertically while remaining parallelto the valve seat, and in performing that function, achieve an excellenteffect not available conventionally.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 1C illustrate vertical cross-sectional views of a checkvalve according to a preferred embodiment of the present invention.

FIG. 2 is a perspective view illustrating a support member used in theembodiment illustrated in FIGS. 1A, 1B and 1C.

FIGS. 3A, 3B and 3C illustrate the support member shown in FIG. 2, whileFIG. 3A is a top view, FIG. 3B is a bottom view, and FIG. 3C is a sideview.

FIGS. 4A and 4B illustrate a different support member used in theembodiment illustrated in FIGS. 1A, 1B and 1C, while FIG. 4A is a topview and FIG. 4B is a vertical cross-sectional view.

FIGS. 5A and 5B are cross-sectional views of a state of use of the checkvalve of the conventional technique described in Japanese UnexaminedPatent Application No. 2010-60110.

FIGS. 6A, 6B and 6C are vertical cross-sectional views illustrating theconventional example.

FIG. 7 is a perspective view illustrating a support member used in theconventional example illustrated in FIGS. 6A, 6B and 6C.

FIGS. 8A, 8B and 8C illustrate the support member shown in FIG. 7, whileFIG. 8A is a top view, FIG. 8B is a bottom view, and FIG. 8C is a sideview.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Next, a preferred embodiment of the present invention will be describedwith reference to drawings.

FIGS. 1A, 1B and 1C illustrate vertical cross-sectional views of apreferred embodiment of a check valve which is the present invention.The overall configuration is substantially similar to that of theconventional technique shown in FIGS. 6A, 6B and 6C and is configured inthat an inflow opening 2 and an outflow opening 3 are formed in acylindrical shape on both ends, respectively, and include: a case body 1made of, for example, an aluminum die cast forming a cylindricallyshaped valve seat 4 having a predetermined length in an axial directionbetween the inflow opening 2 and the outflow opening 3; a disk shapedvalve body 5 having an outer diameter slightly smaller than the innerdiameter of the valve seat 4 and disposed with the ability to move in anaxial direction of the valve seat 4 due to a larger diameter than theinner diameter of the inflow opening 2; and a support member (retainer)6 for the valve body 5 disposed between the outflow opening 3 of thevalve seat 4 and the valve body 5.

Further, the support member (retainer) 6, as illustrated in FIGS. 2, 3A,3B and 3C, is provided with protruding support pieces 64 on the supportmember (retainer) 6 shown in FIGS. 1A, 1B and 1C protruding upward(valve body 5 direction) standing (90° in this embodiment) at mutuallyequivalent angles from the center on a circular plate shaped base seat61 forming an outflow window 62 in the center on an open edge 63 of theoutflow window 62 formed in the center of the base seat 61 and insertedin a circular groove formed between the valve seat 4 and the outflowopening 3 of the check valve shown in FIGS. 1A, 1B and 1C.

Further, with the support member (retainer) 6 as illustrated in FIGS. 2,3A, 3B and 3C, each support piece 64 of the support member (retainer) 6supporting the valve body 5 has a linear (or planar) support part on thetop portion for leveling the valve body 5 at least in a radial directionof the base seat 61.

Note that, the support member (retainer) 6 in this embodiment, similarto the embodiment shown in FIGS. 7, 8A, 8B and 8C, has support pieces 64to support the valve body 5, formed by being cut out, on the open edge63 of the outflow window 62 of the circular base seat 61 having a fluidoutflow window 62 with a predetermined diameter in the center formed by,for example, punching a metal plate such as brass or the like having anappropriate thickness, and the support pieces 64 are erected by bendingin an intersecting direction with the base seat 61. Particularly,because the support pieces 64 are raised in a direction to intersectwith a radial direction of the base seat 61 rather than in the radialdirection, the support pieces 64 have a linear (or planar) support parton the top portion for leveling the valve body 5 at least in a radialdirection of the base seat 61.

In this embodiment, using the support member (retainer) 6 configured inthis manner, as shown in FIG. 1A, the valve body 5 is supported by thesupport pieces 64 of the support member (retainer) 6 due to fluidflowing in from the inflow opening 2 pressing the valve body 5 disposedin the valve seat 4 in a direction toward the outflow opening 3. Thefluid flowing out to the outflow opening 3 from the outflow window 62 ofthe support member (retainer) 6 via the space 42 formed between thesupport pieces 64 and the inner circumferential surface 44 of the valveseat 4 and from the gap 41 formed between the top surface 43 of thevalve seat 4 and the valve body 5.

At this time, in this embodiment, the support piece 64 of the supportmember (retainer) 6 is in a shape that extends in the radial directionof the base seat 61, and instead of point contact against the valve body5 as in the conventionally known check valve shown in FIGS. 6A, 6B and6C, the support piece 64 supports the valve body 5 with at least alinear contact such that the valve body 5 does not tilt or deflect andcan move oscillating in the valve seat 4 in an axial direction in anextremely stable disposition reliably thereby preventing tilt anddeflection by the valve body 5.

Further, in this embodiment, as illustrated in FIG. 1B, when fluidhaving flowed through the outflow opening 3 flows in reverse toward theinflow opening 2, the check valve operates so that the fluid havingflowed toward the outflow opening 3 flows in reverse through the valveseat 4 and moves the valve body 5 in an axial direction in the valveseat 4 to block the open end 21 of the inflow opening 2, placing thecheck valve in a closed state by the valve body 5 tightly contacting theopen end 21 area of the inflow opening 2 of the valve seat 4 by thefluid pressure of the reverse flowing fluid. Because the valve body 5 issupported by the support member (retainer) 6 in a stable state prior tothe reverse flow, even if there is a reverse flow, the valve body 5moves toward the inflow opening 2 in a state still retaining a flatdisposition.

Moreover, as illustrated in FIG. 1C, with this embodiment, the space 42formed between each support piece 64 of the support member 6 and theinner circumferential surface 44 of the valve seat 4 is narrower thanthe conventionally known check valve shown in FIGS. 6A, 6B and 6C, andtherefore, the range of play in the valve body 5 is reduced andsticking, as in the conventionally known check valve, does not occureven if the valve body 5 tilts for some reason while open.

In addition, FIGS. 4A and 4B illustrate a different embodiment of thesupport member (retainer) 6 of the present invention. In thisembodiment, the entirety of the support member (retainer) 6 is formedof, for example, an injection molding using a hard synthetic resinmaterial, and because this does not require a step to machine fold thesupport piece 64, working is easier and a more stable item can beprovided. Particularly, it is possible to form the support part of thesupport piece 64 flat with a wider width than the thickness of thematerial in the previous example embodiment to thereby employ a morestable support member (retainer) 6.

In this manner, the support member (retainer) 6 used in the embodimentsis not limited in material or method of manufacture, and as long as thesupport piece 64 erected on the base seat 61 is formed in a linear orplanar shape having a length in a radial direction to the base seat 61,the effect can be demonstrated.

All features, elements, components, functions, and steps described withrespect to any embodiment provided herein are intended to be freelycombinable and substitutable with those from any other embodiment. If acertain feature, element, component, function, or step is described withrespect to only one embodiment, then it should be understood that thatfeature, element, component, function, or step can be used with everyother embodiment described herein unless explicitly stated otherwise.This paragraph therefore serves as antecedent basis and written supportfor the introduction of claims, at any time, that combine features,elements, components, functions, and steps from different embodiments,or that substitute features, elements, components, functions, and stepsfrom one embodiment with those of another, even if the followingdescription does not explicitly state, in a particular instance, thatsuch combinations or substitutions are possible. Express recitation ofevery possible combination and substitution is overly burdensome,especially given that the permissibility of each and every suchcombination and substitution will be readily recognized by those ofordinary skill in the art upon reading this description.

In many instances entities are described herein as being coupled toother entities. It should be understood that the terms “coupled” and“connected” (or any of their forms) are used interchangeably herein and,in both cases, are generic to the direct coupling of two entities(without any non-negligible (e.g., parasitic) intervening entities) andthe indirect coupling of two entities (with one or more non-negligibleintervening entities). Where entities are shown as being directlycoupled together, or described as coupled together without descriptionof any intervening entity, it should be understood that those entitiescan be indirectly coupled together as well unless the context clearlydictates otherwise.

While the embodiments are susceptible to various modifications andalternative forms, specific examples thereof have been shown in thedrawings and are herein described in detail. It should be understood,however, that these embodiments are not to be limited to the particularform disclosed, but to the contrary, these embodiments are to cover allmodifications, equivalents, and alternatives falling within the spiritof the disclosure. Furthermore, any features, functions, steps, orelements of the embodiments may be recited in or added to the claims, aswell as negative limitations that define the inventive scope of theclaims by features, functions, steps, or elements that are not withinthat scope.

DESCRIPTION OF THE REFERENCE NUMERALS

-   -   1 case body    -   2 inflow opening    -   3 outlet opening    -   4 valve seat    -   5 valve body    -   6 support member (retainer)    -   21 open end    -   41 gap    -   42 space    -   43 top portion    -   44 inner circumferential surface    -   61 base seat    -   62 outflow window    -   63 open edge    -   64 support piece

What is claimed is:
 1. A carburetor comprising: a body; a fuel passagepositioned within the body; and a check valve positioned within the fuelpassage, the check valve comprising: a case body having an inflowopening, an outflow opening larger than the inflow opening, a valve seatpositioned between the inflow and outflow opening, a support memberremovably positioned between the valve seat and the outflow opening,wherein the support member is independent from the valve seat andextends beyond an outer perimeter of the valve seat, and a valve bodylarger than the inflow opening and moveable between the valve seat andthe support member, the support member including a plurality of supportpieces providing a linear support for linearly leveling the valve bodyat least in a radial direction from an axis extending between the inflowand outflow openings.
 2. The carburetor according to claim 1, where inthe valve seat is cylindrically shaped with cylindrically shaped inflowand outflow openings formed at opposing ends respectively on each end ofthe valve seat, the valve seat having an inner diameter larger than theinflow opening and a predetermined length in an axial direction formedbetween the inflow and outflow openings; wherein the valve body ishaving an outer diameter smaller than the inner diameter of the valveseat, the valve body being moveable in the axial direction within theinner diameter of the valve seat; wherein the plurality of supportpieces of the support member protrude from a disk shaped base seat ofthe support member toward the valve body and are formed centrally on anopen edge of an outflow window formed in the center of the disk shapedbase seat; wherein each of the plurality of support pieces of thesupport member supporting the valve body has a linear support part on atop portion for linearly leveling the valve body at least in a radialdirection of the base seat.
 3. The carburetor according to claim 2,wherein a linear support part of each of the plurality of support piecesof the support member extends beyond an outer perimeter of the valvebody.
 4. The carburetor according to claim 2, wherein the base seat andthe plurality of support pieces are integrally form from one piececonstruction.
 5. The carburetor according to claim 4, wherein thesupport member comprises a metal.
 6. The carburetor according to claim4, wherein the support member comprises a synthetic resin material. 7.The carburetor according to claim 1, wherein the valve body is in spacedrelation with a top surface of the valve seat and supported on the topportion of the plurality of support pieces in a level orientation atleast in a radial direction when the check valve is in an open state. 8.The carburetor according to claim 1, wherein the valve body abuts a topsurface of the valve seat when the check valve is in a closed state. 9.The carburetor according to claim 1, wherein the plurality of supportpieces of the support member are positioned in spaced relation with theinner diameter of the valve seat forming a gap there between.
 10. Acarburetor comprising: a body, a fuel passage positioned within thebody, and a check valve positioned within the fuel passage, the checkvalve comprising a case body having a valve seat, the valve seat havingone or more internal walls defining a cavity extending axially along alongitudinal axis between an inflow opening and an outflow opening, thevalve seat having a cross-sectional area larger than a cross-sectionalarea of the inflow opening; a valve body having a cross-sectional areasmaller than the cross-sectional area of the cavity and being moveablein the axial direction within the cavity of the valve seat; a supportmember being removably disposed between the valve body and the outflowopening of the valve seat, wherein the support member is independentfrom the valve seat and extends beyond an outer perimeter of the valveseat; and a plurality of support pieces of the support member providinga planar support for linearly leveling the valve body at least in aradial direction from the longitudinal axis.
 11. The carburetor of claim10, wherein the plurality of support pieces are positioned about anoutflow window formed in a base of the support member and protrude fromthe base in a valve body direction; wherein each of the plurality ofsupport pieces of the support member support the valve body on a planarsupport part on a top portion for linearly leveling the valve body atleast in a radial direction of the base; wherein each of the pluralityof support pieces has a planar support part on the top portion forleveling at least in a radial direction of the base seat by raising eachof the plurality of support pieces to face in a direction to intersect adirection toward a center of the base seat.
 12. The carburetor of claim10, wherein the planar support part of each of the plurality of supportpieces of the support member extends beyond an outer perimeter of thevalve body.
 13. The carburetor of claim 11, wherein the planar supportpart of each of the plurality of support pieces of the support memberextends beyond an outer perimeter of the valve body.
 14. The carburetorof claim 11, wherein the base seat and the plurality of support piecesare integrally formed from one piece construction.
 15. The carburetor ofclaim 14, wherein the support member comprises a metal.
 16. Thecarburetor of claim 14, wherein the support member comprises a syntheticresin material.
 17. The carburetor of claim 11, wherein the valve bodyis in spaced relation with a top surface of the valve seat and supportedon the top portion of the plurality of support pieces in a levelorientation at least in a radial direction when the check valve is in anopen state.
 18. The carburetor of claim 11, wherein the valve body abutsa top surface of the valve seat when the check valve is in a closedstate.
 19. The carburetor of claim 10, wherein the plurality of supportpieces of the support member are positioned in spaced relation with aninner surface of the one or more walls of the valve seat forming a gapthere between.